Rail clamp for machine tools



May 19, 1953 J. M. WALTER RAIL CLAMP FOR MACHINE TOOLS Filed Sept. 29,1948 1N VEN TOR.

ATTORNEYS- Q Q dmv M MLT'EK. BY 4. 44 M Patente'd May 19, 1953 RAILCLAMP FOR MACHINE TOOLS John M. Walter, Cincinnati, Ohio, assignorto.The

G. A. Gray Company, Cincinnati, Ohio, a corporation of Ohio ApplicationSeptember 29, 1948, Serial No. 51,737

6 Claims. (01. 9 -1) This invention relates to a rail clamp for machinetools, and more particularly to a clamp for clamping the rail withrespect to the columns in such machine tools as planers, boring millsand the like.

It has been conventional to provide clamping.

means to clamp the rail to the columns in a desired position ofadjustment, but the clamping means has heretofore always been soarranged that the clamping effect was normal to the di' rection ofmovement of the rail on the columns, and no lateral clamping effect hadever been attained.

It is an object of my present invention, therefore, to provide a novelclamping arrangement in which a lateral clamping effect is obtained inaddition to the normal or conventional clamping effect.

It is a further object of my invention there-' fore to achieve thislateral clamping effect by a relatively simple modification of existingclamp-' ing means, whereby the clamping means of the present invention,although more effective than any known heretofore, will be verylittlemore expensive than the present types of clamping means.

These and other objects of my invention which will be pointed outhereinafter, or which will become apparent to one skilled in the art asthe description proceeds, I accomplish by that cer tain construction andarrangement of parts of which I shall now describe an exemplaryembodiment. Reference is made to the drawings forming a part hereof, andin which:

Figure 1 is a horizontal cross-sectional view through the columns of aplanar or the like, showing the relation of the rail thereto andillustrating the clamping means.

Figure 2 is a detailed view of one of the clamps in plan with parts incross-section.

Figure 3 is a fragmentary. vertical cross-sectional view taken on theline 3-3 of Figure 1.

Figure 4 is a fragmentary cross-sectional view taken on the line 4--4 ofFigure 3.

I shall first describe so much of the structure of a conventional planarcolumns and rail and conventional means as is necessary to anunderstanding of the present invention. Thus, the columns of the machinetool are indicated at I and the rail arranged for travel thereon isindicated at II. Relative movement between the rail II and columns IIIis accomplished on the cooperating ways Illa and Ila. A portion of therail indicated generally at I2 enters into a recess between the columnsIII and contains the actuating mechanism for the rail clamping means. Asbest seen in Figure 3 there is provided a motor I3 and a speed reducerI4 which drives a threaded shaft I5. The screw I5 engages a nut I6having a T-shaped head IBa fitting within a boss ll of the cross-bar I8so as to be non-rotative with respect to the bar I8. The nut is held inplace in the boss I1 by meansof a washer I9,

engaging over the shaft I5, pressed against the boss IT by means of ahelical spring 20 which bears at its other end against a portion of therail casting Ill). The end of the shaft I5 as at I5a has a bearingin theportion I Ib.

Asthe shaft I5 rotates the nut I6 will travel along it toward the rightor left as seen in Figures 3 and 4, and movement of the nut will carry.

with it the cross bar It. At each end the cross bar I8 engages a lever2| pivoted in the rail as at 22 so that the rotation of the screw I5produces rocking of the levers 2I about their pivots 22. Each of thelevers 2I is provided with a recess 23 within which is pivotally mountedas at 24 a rocking equalizing member 25 having contact elements 26 and2'I. The members 26 and 21 engage respectively the push rods 28 and v29which actuate the clamping members to be described hereinafter. Byvirtue of the mounting of the member 25 an equal thrust is exerted onthe members 28 and 29 when thelever 2| is rocked in a counterclockwisedirection, as seen in Figure 3.

Referring now to Figure l, the push rods 28.are

shown as engaging respectively the ends of the levers 30, the other endsof which as at 3I engage the shoulders 32 on the columns. The levers 30are secured to the rail by means of the screws 33 which are threadedinto the rail II. The heads of these screws 33 have a sphericalunderside at 34 cooperating with a spherical counterbore in the lever 30and the bore through the lever 30 is oversize so that the lever 30 mayrock slightly with respectto its bolt 33, thus the bolt 33; cooperatingwith the spherical counterbore in the lever 30 provides a ball andsocket action. When the motor I3 is energized causing the screw I5 torotate rocking the lever 2I in a counter-clockwise direction so as toexert a thrust on the push rods 28 (this thrust on the levers 30 beingin an upward direction as seen in Figure 1), each of the levers 30 isrocked about its bolt and socket joint so as to produce a downwardthrust of the edge 3| against the shoulder 32, thus clamping the rail tothe columns. The clamping system thus far described is in all respectsconventional.

The clamping means of my invention are thus seen at the upper portion ofFigure 1 which in the particular instance illustrated are actuated bythe lower push rods 29. While the levers 30 of the conventional type maybe considered as levers f the first class, the clamping members 40,according to my invention, may be considered as levers-cf the secondclass. These levers-have the portions 41 engaging the shoulders 42' ofthe columns, and they are also provided with the bolts 43 having theball and socket action- -44, all as described above in connection withthe levers 30. The bolts 43 however instead of being threaded into therail are threaded into the wedge blocks 45. These wedge blocks aredisposed in a space between each column and the rail and are constrainedto travel. up and. down: with the rail by the guide plates 46. Asillustrated these wedge blocks have a straight side 45a arranged tocoact with the straight surface on the column, and they have the angularsun"- face-ESZ J arranged to cooperate with the :-angul ar surface 2b onthe: rail. Thus, when pressur'e is exerted by the push rods 29 thelevers Mi -are rocked about their fulcrum: :at- M and draw the. wedgeblocks 45 upwardly. By the :coaction of the surfaceslfiw and 45bala-teral clamping effect is-al'so attained and, therefore, any lateralplay is eliminated.

the drawings: L'have shown an arrangement which has provensati'sfiactory wl-iere- 2 of the usual 4 clamps are according to myinvention. It will be clear that there may be installations where only asingle pair of-clamps according to my invention may be required,oritmaybedcs-i'rable a 4-cl'amp arrangements: to all 4 theclampsaccording to my invention.

It will also becl'ear numerous modifications may be made in details: ofconstruction:- without-departing from the spirit of rnyinvenvention.Itherefore donotintend tobe limited otherwise than asset forth in theclaims which fOHUW'.

Having-now f-ully d'escribed myinventiom what li claim as and desire tosecureby rictters Patent is:

1; 111a; machine tool having columns and-a nail arranged to: tizavelithereon; by: means of? co-- operating ways, there being spaces betweensaid columns and rail longitudinallyof the directionof relative movementof said columnsand-1 rail;

spaces shaving: converging side walls in a direction. normal thereto, apair of clamps flcr clamping said rail-with:v respect. to said columnsand each comprisingza lever oilthyssmhdl class having its fulcrum: ononeof saidbolumns and the force being: appliedfronrsaid rail; and' th'e:load: comprising-a wedge block disposed iii each said space andse'cuvedto: one" of said levers be tween. said fulcrurm and said force;said-wedge blocks, when. force is. :applied to .saidtlevers, extgagingrsai'di converging walls. to exert a-alateval clamping actionbetween said: co'lumnsrand': rail.

2. In a machine tool having columns and a rail arranged to travelthereon by means of cooperating ways, a pair of clamps for clamping saidrail with respect to said columns, each clamp comprising a wedge blockbetween one of said columns and the rail, means secured to said rail andengaging said blocks to constrain said blocks to move with-said rail, alever secured to each of said'blocks and having a portion engageablewith one of said columns, said wedge blocks adapted to exert a wedgingaction between said columns. and: said rail upon actuation of saidlevers.

3 13h amachine tcol having columns and a rail arranged to travel thereonby means of cooperating ways, a pair'of clamps for clamping said railwith respectlto said columns, each clamp comprising a wedge blockbetween one of said columns and the rail, means secured to said rail andengaging said blocks to constrain said blocks to: mate with: said'maiipa lever otfxthe :second' class secured to: eachzof: saidbiocksan'dzhaving its: mil-- crumon; one of said columns, the; force benigta'pplied: toeach or saidll'eversafrom thera'i'l, andisaidi wedge blocksconstituting the loads and; exerting. al'ateral'sclarmping-action.between said columns and said upon a'ctuaifion' ofsa'id levers-1 4''..III. tut-machine toolzzhaving cclumnszand: axrail-v arranged; toatravelthereon by mean .0fcooper-ating ways-,. :a firstpair of clamps adjacentthe bottom-and at the rear of said rail tor clamping sa id :railywi-th'respectto-saidi columns, each clamp comprsing a wedge block between oneoi said columns and the rail, means secured. to-said rail andengagingsaidblocks-toconstrain-said-blockstor move.- mth saidrail, alever.secured to-each' ot said blocks andihaving. a-portion' engageable withone of said columns, said wedge blocks adaptedto-exert-a w-edging actionbetween: said colunms and. said railupon actuation ofisaid levers; andan. additional. pair of. clampsadjacent the top and. at the front ofsaid. rail tosecure said rail in cooperation withsaidfirst pair ofclamps.

.5.. A.-m'achiI-ietool accordingto claim- 2, whereinmeans areprovided-tor equalizing the actuating forces on said levers.

6 vA machine :tool accocding to claim 4,,w-hereintmeanss-areprovided.for equalizing the actuatingv forces on the leversof said first pair ofclamps; means. are provided on equalizing the: forces on thesclampsotlsaidladditionalpair, and meansrare provided forequalizing the forcesapplied, to. said means:-

JOHN M. WALTER Refenences Cited in the file ofthispatent- UNITED -Sl?A'I ES* PATENTS Number Name- Date 1 37-33904 Muller July '30; 159 181,942,414 Eumsenet'al Jan. 9; 1934* 1 976 17 13 Ca-rd ull'o' Oct. 16;I934 2,649l8'42 Kli'ng Aug. 4, I936 2'jl 7i8di I-Tailenbecket all Jan;23, -1"40

